6.1.7 Sockets.AbstractSocket: socket options

soLinger

Answer the number of seconds that the socket is allowed to wait
if it promises reliable delivery but has unacknowledged/untransmitted
packets when it is closed, or nil if those packets are left to their
destiny or discarded.

soLinger: linger

Set the number of seconds that the socket is allowed to wait
if it promises reliable delivery but has unacknowledged/untransmitted
packets when it is closed.

soLingerOff

Specify that, even if the socket promises reliable delivery, any
packets that are unacknowledged/untransmitted when it is closed
are to be left to their destiny or discarded.